Method and device for medium transportation bridge

PROBLEM TO BE SOLVED: To prevent the waste of a medium by reducing the un-exposed area of the medium. SOLUTION: The first stage of a bridge 10 is provided with a first roller pair I where the first stage is detachable and also which is independently driven so as to be replaced with a winding cassette as desired. A friction driving device inside an image setter 14 is applied to the both of driving in the arranged first stage or in the winding cassette. When the first stage is detached, the automatic adjusting device of the bridge 10 balances the pivotably attached bridge 10.